LinkedIn IPO Sizzles

LinkedIn Corp.'s initial public offering is becoming a spectacle for Silicon Valley start-ups and investors, providing the first test of whether the public markets can sustain the soaring private-market valuations of social-media companies.

The early signs are that public investors are ready and willing. On Tuesday, LinkedIn raised the expected offering price range for its shares to between $42 and $45 a share, up from its previous price range of $32 to $35 apiece. The higher offering price puts the valuation of the Mountain...